Crimping die

ABSTRACT

A TWO PART DIE CRIMPS A WIRE CONDUCTOR TO A CONNECTOR BARREL. THE BARREL IS COVERED BY A PLASTIC INSULATING SLEEVE THAT FORMS A SHROUD FOR A SHORT LENGTH OF THE CONDUCTOR EXTENDING OUT OF THE BARREL. ONE PART OF DIE CRIMPS THE BARREL TO THE CONDUCTOR AND IS FORMED WITH A CHANNEL INTO WHICH THE PLASTIC OF THE SLEEVE FLOWS DURING CRIMPING TO FORM A RIDGE THAT LIMITS THE EXTRUSIONS OF THE SLEEVE SO AS TO PRESERVE ITS INSULATING VALVE. THE OTHER PART OF THE DIE PRESSES THE SHROUD PORTION OF THE SLEEVE AGAINST THE CONDUCTOR. A STOP DETERMINES THE DEGREE OF MOVEMENT BETWEEN THE TWO PARTS OF THE DIE AND THEREFORE THE PRESSURE AGAINST THE SHROUD PORTION OF THE SLEEVE.

2 Sheets-Sheet 1 XNVENTOR.

w. R. BOWDEN, JR., ET AL CRIMPING DIE March 16, 1971 Filed Nov. 1, 1968Y E a M 0 m w r a? T. Raw fl Hum wan 0E0 Nm MEW arch 16, WW W. R.BOWDEN, JR. ET 5 CRIMPING DIE 2 Sheets-Sheet 1% Filed NOV. 1, 1968INVENTOR.

United States Patent 3,570,097 CRIMPING DIE Wade R. Bowden, Jr.,Milford, Ernest L. Cheh, Darien, and Nino Suffredini, Monroe, Conn.,assignors to Burndy Corporation Filed Nov. 1, 1968, Ser. No. 772,723Int. Cl. H01r 43/04 US. Cl. 29--203 11 Claims ABSTRACT OF THE DISCLOSUREA two part die crimps a wire conductor to a connector barrel. The barrelis covered by a plastic insulating sleeve that forms a shroud for ashort length of the conductor extending out of the barrel. One part ofdie crimps the barrel to the conductor and is formed with a channel intowhich the plastic of the sleeve flows during crimping to form a ridgethat limits the extrusion of the sleeve so as to preserve its insulatingvalue. The other part of the die presses the shroud portion of thesleeve against the conductor. A stop determines the degree of movementbetween the two parts of the die and therefore the pressure against theshroud portion of the sleeve.

This invention relates to a die, and more particularly a die which oneof the two coacting halves is itself formed of two relatively movableparts. The die of our invention is particularly adapted for coactionwith a work piece in which two or more parts are formed of differentmaterials, or which have different constructions.

Actually, the die of our invention is adapted for crimping a connectorbarrel to a conductor wire, after the conductor wire has been placedinto the barrel. The barrel is of the type that is formed integrallywith a connector terminal and takes the shape of a sleeve. Prior to thecrimping operation the barrel is insulated by placing on it a plasticsleeve that extends beyond the barrel at one end of the barrel so thatit may constitute a shroud for covering a part of the conductor wireextending outwardly from the barrel. Since the conductor wire covered bythe shroud is formed of a flexing wire covered by plastic material,while the connector barrel is a metal sleeve, the die must necessarilycoact with the plastic shroud in a manner different from its coactionwith the plastic covered metal barrel. This is particularly true becausefrequently a particular form of shroud is required, and many times theshroud is flared prior to the crimping operation. Also, the shroud maybe required to grip the conductor wire in different relationshipsbecause of varying conditions, even though the same connector is used,all as is well known to those skilled in the art.

As a feature of our invention we contribute a moving die portion havingtwo relatively movable parts, with one part adapted to contact what wehave indicated is the shroud portion of the plastic sleeve, the otherpart of the die being adapted to contact the plastic covered metalbarrel of the connector. As a particular feature of the invention, wearrange to press the shroud contacting part of the die downwardly towardthe connector, relatively to that part of the die acting as the crimpingdie for the connector barrel, preferably using a spring for thispurpose. Therefore, it is obvious that the spring projected part of thedie will be the first to contact the work piece, in this case the shroudportion of the plastic sleeve extending beyond the barrel. This contactwill naturally react against the spring, so that the die will first beeffective against the work piece only to the extent that the spring willhold the die against the work piece. The other part of the die ismovable naturally with the press plunger on which it is mounted and willact solidly against the plastic sleeve 3,570,097 Patented Mar. 16, 1971covered portion of the metal barrel for the crimping operation.

By providing a stop for the spring projected die part, so that that diepart can only move against the spring pressure a limited distance, wecan, in effect, make the spring projected part of the die integral withthe crimping die after some relative movement between the two. Throughthe adjustment of the stop mechanism thus making the two parts of thedie integral, the degree of action of the spring projected part of thedie against the shroud may readily be varied and controlled.

This part of our invention contributes a further feature of exceedingimportance. Thus, it will be appreciated that as the shroud is actedupon by the spring projected part of the die, the spring operatingagainst this movable part will be stressed. Therefore, upon completionof the crimping operation, the spring will be effective to press thespring projected part of the die relatively to the other part and toeject the work piece from the moving die so as to leave the connectorresting on the fixed half of the die. This ejection of the work piece,in this case the crimped connector barrel, is of exceeding value andimportance, as those skilled in the art will appreciate.

When the barrel crimping part of the two piece die portion acts againstthe plastic sleeve, and through the plastic sleeve against the metalbarrel, it is obvious that there will be a tendency for a fiow of theplastic material axially of the barrel and beyond the ends of thebarrel, particularly beyond that end of the barrel facing the connectorterminal and from which the inserted end of the wire extends. Naturally,flow of the plastic material endwise of the barrel can greatly decreasethe thickness of the plastic at any particular point, and greatly lowerthe insulating quality of the plastic sleeve if not entirely destroy it.We have contributed a die concept under which the plastic material isitself utilized to prevent plastic flow. This use of the plasticmaterial for preventing flow thereof is exceedingly important because itis impossible to manufacture the die so that it will confine the plasticagainst flow.

Thus, because of the relatively small size of the barrel sleeve and thevery thin section of the plastic sleeve, it is not possible to utilize adie that will crimp and yet will effectively, as by a flange, confinethe plastic sleeve relatively to the metal sleeve. Thus, when placing awire into the barrel, it is the custom of the art to move the wire inthe barrel to a point where its end extends beyond the barrel. In thisway, the operator can determine readily that the wire has been fullyinserted. Also, the end extending beyond the barrel remains uncrimpedafter the crimping operation. It is therefore somewhat larger than thecrimped barrel, and obviously, any attempt to pull the wire outwardly ofthe barrel would require a compression of the uncrimped wire. Naturally,there are many advantages to this manner of bringing about the crimping.However, this protruding end of the wire limits the downward movement ofthe die, and therefore prevents the utilization of a flange effectivefor confining the plastic material against flow.

As a particular feature of this part of our invention concept, weutilize initial plastic flow of the plastic sleeve for creating abarrier against continued plastic flow. Thus, the die of our inventionis formed with a pocket or channel located preferably at the partcoinciding with the end of the plastic sleeve facing the terminal. Whenthe die is applied to the plastic sleeve, the plastic material will flowinto this pocket or channel, and will form a plastic shoulder whichprevents any further flow of the plastic material so that the plasticmaterial moves with the metal of the barrel and forces the metal barrelinto crimping relation to the wire inserted in the barrel.

While we particularly utilize this channel at that end of the connectorbarrel facing the terminal, we also prefer to utilize the same shoulderforming construction at the other end of the connector barrel where theplastic sleeve extends beyond the barrel to form the shroud to which wehave earlier referred.

We have thus outlined rather broadly the more important features of ourinvention in order that the detailed description thereof that followsmay be better understood, and in order that our contribution to the artmay be better appreciated. There are, of course, additional features ofour invention that will be described hereinafter and which will form thesubject of the claims appended hereto. Those skilled in the art willappreciate that the conception on which our disclosure is based mayreadily be utilized as a basis for the designing of other structures forcarrying out the several purposes of our invention. It is important,therefore, that the claims be regarded as including such equivalentconstructions as do not depart from the spirit and scope of ourinvention, in order to prevent the appropriation of our invention bythose skilled in the art.

Referring now to the drawings;

FIG. 1 is an isometric view showing the lower and upper halves of a dieconstructed in accordance with the invention to be described in thisapplication;

FIG. 2 is a vertical section illustrating the die parts of FIG. 1 asthey are related to one another in an actual crimping machine. In thisfigure a connector is illustrated in position on the lower half of thedie with the upper half of the die about to descend into contact withthe connector for effecting the crimping operation as well as thedesired deformation of the shroud covering the conductor wire;

FIG. 3 is a view of the parts of FIG. 2 after the upper portion of thedie has contacted the connector and has completed the crimpingoperation;

FIG. 4 illustrates in elevation and partial section the adjustable stopfor one of the parts of the upper half of the crimping die fordetermining the relationship between the crimping operation on thebarrel of the connector, and the deformation of the shroud covering thewire just outside the connector barrel;

FIG. 5 illustrates in partial section the position of the upper half ofthe die of FIG. 1 just as it is about to deform the shroud and alsocrimp the barrel of the connector against a wire conductor;

FIG. 6 illustrates the parts of FIG. 5 just after the crimping operationhas been completed and shows the barrel crimped against the conductingwire, and the shroud portion of the plastic sleeve suitably deformed asrequired relatively to the wire conductor;

FIG. 7 illustrate one form of connector that may be utilized with thedie of our invention;

FIG. 8 illustrates the connector of FIG. 7 after the barrel portion ofthe connector has been covered by a plastic sleeve and a wire conductorinserted into the barrel in advance of the crimping operation;

FIG. 9 illustrates the connector of FIG. 8 after the crimping operationhas been completed and the shroud portion of the plastic sleeve has beendeformed;

FIG. 10 is a section through the crimped connector barrel taken alongline 1010 of FIG. 6.

"Referring now more particularly to the drawings. FIG. 7 shows inisometric one form of a connector that is adapted to be acted upon bythe die of our invention. The part designated by reference numeral 10 ofFIG. 7 is termed a terminal portion. Reference numeral 11 indicates thebarrel portion of the connector, it being understood that the connectoris actually formed of one piece of metal that is stamped and bent, allas is standard in the art. In FIG. 8, the barrel portion 11 is showncovered by a plastic sleeve 12, this sleeve being well illustrated alsoin FIG. 5, in which its relation to the connector and the wire to becrimped to the connector is also well illustrated. It will be noted thatthe plastic sleeve 12 is outwardly flared as best shown at 15 in FIG. 5and FIG. 8. This flaring takes place just beyond the end 16 of theconnector barrel 11, and its purpose is to accommodate the insulation 17of a wire conductor 18. That portion of the plastic sleeve 12 coveringthe insulation 17 is termed a shroud, and is designated by the referencenumeral 19 in both FIGS. 5 and 8.

For bringing about the crimping operation, it is customary to remove theinsulation 17 from the end of the conductor wire 18 so that only thebare wire 18 will lie within the barrel 11 as is also well illustratedin FIGS. 5 and 8. It will be noted that the end of the connector wire 18protiudes beyond the terminal facing end of the barrel 11. This relationof the wire 18 to the barrel 11 is important because, once the crimpingoperation is completed, an uncrimped and enlarged wire portion will beoutside of the barrel and will effectively prevent the pulling of thewire 18 through the barrel 11, since such pulling would require thecompression of the wire 18 in order to make it to conform to the innerdiameter of the barrel 11. As was earlier emphasized, this end of thewire 18 also presents a problem because it limits die movement.

A simple viewing of the wire conductor 18 and its relation to thevarious parts illustrated in FIG. 5, will amply illustrate that ifcrimping pressure is applied to the sleeve 12 and against the barrel 11,the plastic material of the sleeve will flow axially of the barrel,since substantial pressures are required for crimping. Therefore, itfollows that parts of the plastic sleeve 12 would be so extruded thatlittle or no insulation would remain to protect some parts of the barrel11. We have conceived the idea of preventing extrusion or axial flow ofthe plastic sleeve 12 relatively to barrel 11 through utilizing aflanged die to cover the end of the plastic sleeve 12. Unfortunatelysuch relationship of a die to the plastic sleeve is partially preventedby the presence of the projecting end of the conductor wire 18. In otherwords, because the wire 18 projects beyond the barrel 11 as shown inFIGS. 5, 8 and 9 toward the terminal portion 10 of the connector, it isnot possible for a die flange to cover that end of the plastic sleeve 12that terminates at the connector barrel, since such a flange wouldobviously form an obstacle to the downward die movement of the crimpingoperation.

All this will appear more clearly after a further description of ourinvention is presented. In any event, because we have found that it isimpossible to eliminate extrusion or axial flow of the plastic sleeve 12relatively to the barrel 11 through the use of containing or limitingdie surfaces, we have conceived, as is set forth eariler in thisapplication, the feature of controlling the extrusion or flow of theplastic sleeve by forming a self-limiting ridge integral with theplastic sleeve during the first portion of the die closing operation, sothat in effect, the plastic sleeve itself prevents the extrusion thereofand the possible baring of the barrel 11 so as to destroy the insulatingvalue of the sleeve 12.

We believe that the form of the die of our invention is well illustratedin FIGS. 1, 5, and 6 to which reference is now made. In these figures itwill be noted that the lower or fixed half of our die designated byreference numeral 20 is formed with an upstanding shroud crimpingportion 21 and a barrel crimping portion 22. The barrel crimping portionis formed with a flange 23 that is adapted, as best illustrated in FIG.5, to lie against the forward end surface 24 of the plastic sleeve 12.This end surface 24 lies in the same plane and is coincident with theend surface 25 of the barrel 11 of the connector. The flange 23 formswith the remainder of the die portion 22 a channel 26, this channel 26lying between the flange 23 and the crimping surface 27 of the dieportion 22. A somewhat similar channel 28 is formed between the otherend of the crimping surface 27 of the lower die portion 22, and theshroud crimping surface 31 of the shroud crimping die portion 21.

The upper or movable half of the die coacting with the lower fixed half20 is designated by reference numeral 35 in FIG. 1 and also in FIG. 5.The upper die portion is formed complementary with the lower die portionexcept that the shroud crimping part thereof is slidable relatively tothe barrel crimping part as was earlier outlined, and as will bedescribed presently. The barrel crimping part of the upper die is formedwith a flange 36 that is similar to the flange 23, and there is achannel 37 between the flange 36 and the crimping surface 38 of theupper die. A further channel 39 is formed complementary to the channel28 bet-wen the crimping surface 38 .for the barrel, and the crimpingsurface 40 for the shroud 19.

Let us now examine FIG. 6 in order to determine just what happens whenthe two die halves of FIG. approach one another to complete the crimpingoperation. The flange 36 of the upper die portion will approach theconnector wire 18 as it, together with the flange 23 of the lower dieslide along the end surface 25 of the barrel 11. While the upper andlower flanges 36, 23 will act somewhat to contain the plastic sleeve 12so as to prevent extrusion thereof axially, it is obvious that therelationship of the parts will be ineffective to prevent considerableextrusion of the plastic material as the two die halves approach oneanother. At this point it will be noted that the protruding end of theconductor 18 will prevent the use of a fully effective flange 36, andthat there is a space through which plastic can flow.

It will be noted that the channel 26 and the channel 37 arecomplementary, and form a peripheral chamber, in effect, into which theplastic from the sleeve 11 may flow axially as the die parts moverelatively to one another from the position of FIG. 5 to the position ofFIG. 6. This flow is such that a shoulder portion 50- is formed at theend of the plastic sleeve 12. This shoulder, once formed, will obviouslyfirst limit and then prevent plastic flow. Therefore, it may be said,that the channel portions 26, 37, permit the formation of aself-limiting shoulder through a controlled flow of the plastic materialof the sleeve 12. Of course, the two channels 28 and 39 will also form ashoulder lying between the barrel covering portion of the sleeve 12 andthe portion 19 of the sleeve 12 that is the shroud for the wireconductor insulating portion 17.

It will be noted that the shroud of the sleeve 12 is adapted to betapered as illustrated in FIG. 6 by the surfaces 31 and 40 of the shroudforming die parts. In this manner, the shroud is deformed so as to gripeffectively the insulation 17 of the wire conductor 18. A further effectof the tapering of the die portions 31 and 40 is to assist in preventingflow of the plastic material axially. Thus, in FIG. 6, it can readily beascertained that the tapers 31 and 40 will assist the shoulder 55 formedat the right hand end of the barrel 11 on the sleeve 12, in preventingexecessive axial fiow by extrusion of the plastic sleeve 12 during thecrimping operation.

It will be noted in FIG. 6 that the end of the conductor 18 facing theterminal has not been deformed by the crimping operation, and that it issomewhat larger than the inside diameter of the deformed crimped barrel11. As was earlier emphasized, this relatively larger portion of theconnector wire 18 will be very effective in preventing outward pull ofthe connector wire 18 from the connector barrel in the direction of thearrow 56 in FIG. 6.

In FIG. 9, the shoulders 50 and 55 formed by the extrusion of theplastic sleeve 12 are well illustrated. Also well illustrated is thedeformed shroud portion 19. At this point it will be well to indicatethat the two winglike portions 60 of the shroud portion 19 are formed bythe relatively flat surfaces 61 of the lower portion of the die seen inFIG. 1, and similar surfaces on the upper portion of the die. SectionalFIG. 10 illustrates well the shoulder 50 as Well as the cr'imped barrel11 and its relation to the conductor wire 18.

While the lower die portions 22 and 21 are fixed relatively to oneanother, these being the die portions on which the connector barrel 11together with the plastic sleeve 12 rests for the die closing operation,the upper die portion coacting with portions 21 and 22 is formed of tworelatively moving parts as was earlier outlined. This, as was alsoemphasized, is necessary in order to vary the relationship between thebarrel crimping operation and the shroud crimping operation, it beingobvious that frequently it may as an example be desirable to have arelatively loose fitting shroud accompanied by an extremely effectivebarrel crimping operation, and other variations.

Referring now more particularly to the FIGS. 2 and 3, it will be seenthat the upper crimping surface 40 for the forming of the tapered shroud19 is integral with die part 62. This part 62 is slidable relatively tothe upper die portion 35 to which reference has already been had. Theflange 36 and the upper crimping surface 38 are integral with this dieportion 35 as is apparent. It will of course be further appreciated thatthe die portion 35 (FIG. 1) is formed with a suitable opening 63 foraccommodating the upstanding die portions 21 and 22 integral with thelower die body 20, so that the upper and lower dies may be brought intosuitable closing and mating relationship.

The die 35 may be fixed in any desired manner to a verticallyreciprocating piston of a standard press. Also, it may be guided in anysuitable manner for vertical movement in a predetermined path so that itwill coact effectively with the lower half of the die 20 that is fixedto the machine in Which the vertically moving piston is mounted. Thevertically moving piston of our invention is designated generally by theletter P, and it will be noted in FIGS. 2 and 3 that the upper surface35a of the die 35 bears against a surface 65 of the piston P so that thepiston P may exert downward pressure on the die part 35 as is required.A locating pin 66 is secured in proper position by a sleeve 67, in turnfixed by a screw 68 to piston P, for locating the die 35 relatively tothe piston P. The die 35 may be suitably guided in its movement with thepiston by a guide body 70 and a plate 71 secured to the guide body as byscrews 72. As was indicated, the manner of mounting of the die 35 andits actuation by a piston P may be in any manner standard in the art.For this reason, this portion of the invention is shown and describedonly generally.

The movable die portion 62 carrying the shroud crimping die part 40 isprojected downwardly relatively to the die part 35 by a spring 75reacting against a lug 76 fixed to the die part 35. A pin 77 fixed tothe die part 35 also guides portion 62. Let us now consider what happenswhen the piston P moves downwardly from its position of FIG. 2 to itsposition of FIG. 3 carrying the upper die 35 toward the lower die 20 andits upstanding die portions 21 and 22 on which now rests a connector ofthe type seen in FIG. 8 whose barrel 11 is covered by a plastic sleeve,a conductor 18 being in the barrel, The shroud forming surface 40 willfirst contact shroud forming portion 19 of the sleeve 12, but verylittle effective pressure will be applied, all pressure being exertedonly through spring 75. After the portion 38 of the upper die 35contacts the plastic sleeve 12 and acts through that plastic sleeve 12against die surface 27 to crimp the barrel 11 against the wire 18,contact will be made between a surface 80 of an adjusting bar 81 (shownin detail in FIG. 4) and a surface 82 of the movable die portion 62.This contact is well illustrated in FIG. 3.

It is obvious that by varying the distance between the upper surface 82of the movable die portion 62 and the surface 80, the point wherepressure is applied to the moving die portion 62 by the piston P may bevaried. In this way, it is possible to vary the relationship between thecrimping of the shroud portion 19 of sleeve 12 relatively to conductor17, 18, and the crimping of the barrel 11 to the wire 18. For thispurpose we utilize bar 81 shown best in FIG. 4. This bar merely slidesin an opening 85 in the piston P, and in effect, is integral with pistonP. In addition to a stop surface 80, it is equipped with stop surfaces86, and 87, and may have any number of stop surfaces required in orderto vary the relationship between the crimping of the shroud and thebarrel. For indexing the slide 81, the slide has a series of depressions88 and cooperating with these depressions is a spring pressed ball 89carried by piston P. Obviously, the spring pressed ball 89 holds theslide 81 yieldingly in any of its positions to which it is movedmanually.

While the relatively moving die parts are required in order to vary thecrimping relationship has already been emphasized, there is a corollarycontribution made by this sliding relationship. Thus, When the piston Pmoves upwardly from its position of FIG. 3 back to its position of FIG.2, so that the crimped connector may be indexed toward a furtherposition in the machine for severing, as is understood by those skilledin the art, the spring 75 will act to hold the connector in its positionagainst the lower die. In effect, the spring 75 will bring about anejection of the connector from the upper die so as to leave the crimpedconnector in a position on the lower die surfaces 27 and 31 for transferlaterally.

We do believe that those skilled in the art will now appreciate therather considerable contributions of our invention. It is obvious thatby a very simple arrangement of die portions, We are able to determinethe relationship between the crimping of the shroud and the crimping ofthe barrel relatively to the wire conductor 17, 18. We are also able toprevent the flow of the plastic material of the plastic sleeve 12through extrusion under pressure of the two die portions by utilizingthe plastic of the sleeve itself as an obstruction to this flow. Thismethod for preventing such flow of plastic under pressure is in itselfof extreme value.

We now claim:

1. In a crimping die for a metal connector of the type having a terminaland a crimp barrel with a plastic sleeve on said barrel, one end of thesleeve being coextensive with that end of the crimp barrel facing theconnector terminal, the other end of the sleeve extending beyond thesleeve and forming a shroud for a wire extending into said barrel withthe inserted end of said wire just beyond the terminal facing end of thecrimp barrel, a containing flange at one end of said die fitted againstthe terminal facing end of the plastic sleeve together with a crimpingsurface on said die inwardly of said end adapted to be applied againstthe plastic sleeve and therethrough to crimp the barrel covered by saidplastic sleeve, and a channel in said die between said crimping surfaceand said flange for receiving plastic flowing axially toward said flangeduring the crimping action so that a ridge is formed on said plasticsleeve at said terminal facing end.

2. A crimping die assembly for a metal connector of the type having aterminal and a crimp barrel, a plastic sleeve on said barrel, one end ofthe sleeve extending beyond the barrel and forming a shroud for aconductor wire extending into said barrel, comprising a barrel crimpingdie part to be applied to that portion of the sleeve covering said crimpbarrel for crimping the wire to the barrel through the intermediary ofthe sleeve, a shroud crimping die part for crimping the plastic sleeverelatively to a portion of the conductor wire outside the barrel, andmeans mounting said shroud crimping die part for movement relatively tosaid barrel crimping die part upon application of end pressure to saidshroud crimping die part.

3, In the combination of claim 2, the feature of a spring pressing saidshroud crimping die part endwise relatively 8 to said barrel crimpingdie part and toward the plastic sleeve shroud, with said springaccepting pressure when said shroud crimping die part strikes theplastic sleeve, whereby said spring resists movement of said shroudcrimping die part relatively to said barrel crimping die part.

4. In the combination of claim 2, the feature of means for limiting themovement of said shroud crimping part relatively to said barrellcrimping part whereby to adjust the shroud crimping action of saidshroud crimping part.

5. In the combination of claim 3, a press piston in which said dieassembly is mounted with said barrel crimping part moving integrallywith said piston, and an adjustable stop on said piston for limiting themovement of said shroud crimping part relatively to said barrel crimpingpart whereby to adjust the shroud crimping action of said shroudcrimping part.

6. A crimping die or the like for a plastic covered metal sleeve or thelike, comprising a crimping surface and a surface formed to prevent flowof the plastic of said plastic covering the metal sleeve endwise of saidmetal sleeve during application of crimping pressure by said die to saidplastic and therethrough against said metal sleeve.

7. In the combination of claim 6, the feature that said surface of saiddie is formed as a channel or depression into which plastic flows aspressure is applied to said plastic by said crimping surface, wherebythe plastic in said channel forms a limiting shoulder limiting the flowof plastic under pressure and locks the plastic against movementrelatively to said die during application of crimping pressure by saiddie to said plastic.

8. In the combination of claim 7, the feature that at least one end ofthe die is formed with a flange defining one side of said channel, saidflange fitting against the end of the metal sleeve as said die crimpssaid metal sleeve by application of pressure to the plastic coveringsaid sleeve.

9. In the combination of claim 8, the feature that said metal sleeve isa crimp barrel of a connector and that it is covered by a plasticsleeve, one end of the plastic sleeve being coextensive with that end ofthe crimp barrel facing the connector terminal, the other end of thesleeve extending beyond the barrel and forming a shroud for a wireextending into said barrel with the inserted end of said wire justbeyond the terminal facing end of the crimp barrel.

10. In the combination of claim 3, the feature that said shroud crimpingdie part through the intermediary of said spring applies angularpressure to prevent movement of said plastic sleeve in one directionrelatively to said barrel, and a flange on the barrel crimping die partfitting against the end of the plastic sleeve to hold the plastic sleeveagainst movement in an opposed direction on said barrel.

11. In the combination of claim 10, the feature that said flange definesone side of a channel in said die into which plastic flows as pressureis applied to said plastic, whereby the plastic in said channel becomesa limiting shoulder limiting the flow of plastic under pressure andlocks the plastic against movement relatively to said die duringapplication of pressure by said die to said plastic sleeve.

References Cited UNITED STATES PATENTS 3,402,452 9/1968 Mraz 29203THOMAS H. EAGER, Primary Examiner

